i) Field of the Invention
The present invention relates to an automatic analysis apparatus for analyzing organism liquid samples, and particularly to an automatic analysis apparatus provided with an analysis unit for measuring biochemical analysis items and an analysis unit for measuring, immunoassay analysis items.
ii) Description of Related Art
Analysis of organism liquid samples such as blood and urine originated from a patient has been broadly performed in order to obtain information for diagnosis of a disease nature, and automated analysis apparatuses have been used in hospitals and clinical laboratories.
A test result obtained by one automatic analysis apparatus is insufficient for the diagnosis of the disease nature in many cases, and test data needs to be collected from a plurality of analysis apparatuses in such case. An analysis system disclosed in Japanese Patent Unexamined Publication No. 281113/1997 is constituted in such a manner that a multiplicity of types of analysis items can be analyzed by one unit of system. The Japanese Patent Unexamined Publication No. 281113/1997 proposes an analysis system constituted in such a manner that a plurality of analysis units for biochemical analysis are arranged along a conveyance line of specimen racks, the specimen rack from a rack supply section is stopped at either one of the analysis units and samples on the specimen rack are dispensed by pipette nozzles.
Moreover, U.S. Pat. No. 5,470,534 discloses an analysis system constituted so as to arrange a biochemical analyzer, an immunoassay analyzer, a nucleic acid analyzer, and the like along a conveyance path of sample containers in such a manner that the same sample can be measured by the respective analyzers. In this example, it is determined in accordance with an analysis result in a first measurement stage whether or not the sample should be advanced to a second measurement stage. In the first measurement stage, biochemical analysis items are analyzed, and sample needed to be moved to the second measurement stage for determination of disease nature are analyzed by the immunoassay analyzer and/or the nucleic acid analyzer in the second measurement stage.
On the other hand, with apparatuses for automatically analyzing organism liquid samples, it is general to dispense a large number of samples in succession using one dispenser probe, so there is caused a problem that subsequent samples are contaminated by residues of preceding samples on dispenser probe. A known example for handing such carry-over is disclosed, for example, in Japanese Patent Application Unexamined Publication No. 169851/1992. This publication discloses that a row of reaction containers formed on the same circumference are used to execute analysis of the biochemical analysis items for measuring components usually contained in blood, or analysis of immunoassay analysis items for utilizing aggulutination of latex particles to detect antigen and antibody.
Moreover, the Japanese Patent Unexamined Publication No. 169851/1992 describes that wasteful consumption of the cleaning liquid is eliminated by cleaning a reagent dispenser probe, having dispensed a reagent of immunoassay analysis item, with a cleaning liquid for a sufficient cleaning time or with an increased discharge amount of the cleaning liquid, and by cleaning the reagent dispenser probe, having dispensed a reagent of biochemical analysis item, for a short time or with a reduced discharge amount of the cleaning liquid. This publication also points out that even with a probe for dispensing a sample other than the reagent, the wasteful consumption of the cleaning liquid can be eliminated by adjusting a cleaning liquid flow rate.
As another type for dispensing of organism samples, use of a disposable nozzle tip is known. For example, Japanese Patent Unexamined Publication No. 146010/1996 discloses that a tip holder is provided in a movable range of a connection tube capable of connecting thereto the nozzle tip, and after one nozzle tip is conveyed to a tip holder position from a tip rack with a large number of nozzle tips arranged thereon by a movable gripper, the nozzle tip is connected to an end of the connection tube on the tip holder, and that a sample sucked into the connected nozzle tip is discharged to the reaction container, and the nozzle tip is removed from the connection tube in a tip detachment station after discharge of the sample.
Many methods of measuring immunoassay analysis items include an operation of utilizing an antigen-antibody reaction (i.e., immunoassay reaction) to connect a marker material to a solid phase. When it is necessary to analyze the immunoassay analysis items by this method, and biochemical analysis items based on a method for absorption measurement of a reacted liquid resulting from chemical reaction, it is convenient in handling of samples to arrange a plurality of analysis units in the analysis system, and to use the same sample container in common for the respective analysis units. In the U.S. Pat. No. 5,470,534 related to such analysis system, no countermeasure for avoiding a carry-over between samples is disclosed.
With the constitution of using disposable nozzle tips disclosed in the Japanese Patent Unexamined Publication No. 146010/1996, nozzle tips are replaced every sample, and so there is no possibility of influence of carry-overs between samples.
However, every sample entails the connecting operation and detaching operation of a nozzle tip, so that when a large amount of analysis items have to be treated in a short time as in biochemical analysis items, a sufficient treatment ability cannot disadvantageously be obtained.
The Japanese Patent Unexamined Publication No. 169851/1992 has proposed that the same dispenser probe for repeated use is used both for the biochemical analysis items and the immunoassay analysis items, and carry-over is avoided only by cleaning operations. However, in order to inhibit immunoassay analysis items from being affected by carry-overs between specimens from dispenser probes for biochemical analysis, cleaning time and cleaning flow rate need to be considerably increased as compared with usual cleaning with the result that the treatment ability of biochemical analysis is disadvantageously remarkably lowered.
Measurements of immunoassay analysis items such as antigen, antibody, hormone, and virus have to be detected with high sensitivity as compared with biochemical analysis items, but there is a problem that analysis result is susceptible to carry-overs between samples. Therefore, the immunoassay analysis items have a remarkably high necessity of avoiding carry-overs between samples as compared with biochemical analysis items, and so repeatedly used sample dispenser nozzles require careful handling.
It is an object of the present invention to provide an automatic analysis apparatus, which includes an immunoassay analysis unit for utilizing immunoassay reaction and a chemical analysis unit for utilizing chemical reaction, and in which even when a sample from the same sample container is dispensed to the immunoassay analysis unit after dispensing the sample to the chemical analysis unit, analysis results of analysis items given by the immunoassay analysis unit can be prevented from being influenced by carry-overs between the samples.
It is another object of the present invention to provide an automatic analysis apparatus, which gets off substantial degradation in analysis treatment ability of biochemical analysis items and can avoid carry-overs between samples at the time of analysis of immunoassay analysis items even when constituted to convey the same sample to a plurality of analysis units.
The present invention is applied to an automatic analysis apparatus including a first analysis unit for utilizing immunoassay reaction to analyze analysis objects as analysis items in a sample, a second analysis unit for measuring reaction liquids obtained by chemical reaction between the sample and reagents to analyze analysis items, analysis item indicating means for indicating analysis items being analyzed for each sample to a control unit, and a conveying device for conveying samples to at least one of a plurality of analysis units including the first and second analysis units.
In the present invention, there are provided a screen display device for displaying a screen, on which high and low levels of avoiding carry-overs between samples can be selected every analyzable analysis item, and a storage unit for storing carry-over avoidance levels selected through the screen of the screen display device in association with analysis items, and a dispenser nozzle of the second analysis unit is cleaned with water prior to a dispensing operation of a sample, for which analysis by the second analysis unit is necessary but analysis of analysis items having a high carry-over avoidance level is not instructed, and a dispenser nozzle of the second analysis unit is cleaned with a detergent solution and then with water prior to a dispensing operation of a sample, for which analyses by both the first and second analysis units is necessary and analysis of analysis items having a high carry-over avoidance level is instructed.
In a preferred embodiment of the present invention, the first analysis unit comprises a sample dispenser, which uses a dispenser tip for replacement every sample, and the second analysis unit comprises a sample dispenser, which uses a dispenser nozzle for repeated use. Also, the screen displayed by the screen display comprises an analysis item selection column, in which one or more analysis items can be selected from a plurality of analysis items, and a level selection column, in which level of avoiding carry-overs between samples can be selected with respect to the selected analysis item.